A good PCB layout for the MP2104DJ-1.8-LF-Z should include a solid ground plane, separate analog and digital grounds, and a decoupling capacitor (e.g., 10uF) placed close to the VIN pin. Additionally, the input and output capacitors should be placed as close as possible to the IC.
To ensure stability, make sure to follow the recommended component values and PCB layout. Also, ensure that the output capacitor has a low ESR (Equivalent Series Resistance) and is placed close to the output pin. Additionally, a small ceramic capacitor (e.g., 10nF) can be added in parallel with the output capacitor to improve stability.
Although the datasheet specifies a maximum input voltage of 5.5V, it's recommended to limit the input voltage to 5V to ensure reliable operation and prevent damage to the IC.
While the datasheet recommends a specific inductor value and type, you can use a different inductor value or type as long as it meets the recommended inductance range (1.5uH to 3.3uH) and has a similar DCR (Direct Current Resistance) value. However, this may affect the converter's performance and efficiency.
The output voltage ripple can be calculated using the following formula: ΔVout = (Iout * DCR) / (fsw * L), where Iout is the output current, DCR is the inductor's direct current resistance, fsw is the switching frequency, and L is the inductor value.